Diets don't work for the simple reason that it is impossible to stay on them as they just don't fit into our life-styles and become a total drag. Not only that, but rapid weight-loss ones like this one can be positively dangerous, depleting the body of essential vitamins and minerals, potassium, etc.
When one goes OFF a diet, the pounds not only reappear, but you get the added "benefit" of adding even more pounds as you start to crave all those things you were denied on your diet.
So adopt a healthy eating plan and use the pyramid food diagram. You can find this on MayoClinic.com - plus a healthy eating plan. Cut out as many white over-refined products as you can. Start the day with some healthy oatmeal, etc., and don't forget - speed up your metabolism or you won't see any results - healthy eating and exercise go hand-in-glove.